The subtypes they identified are: inflammatory, in which markers such as C-reactive protein and serum albumin to globulin ratios are increased; non-inflammatory, in which other metabolic abnormalities are present; and cortical, which primarily affects younger people, does not cause memory loss at first, but individuals tend to lose language skills.

In a paper released last year, Bredesen showed that making lifestyle, exercise and diet changes to improve the body's metabolism reversed cognitive decline in nine out of 10 patients with early Alzheimer's disease .

“The important implications of [these findings] are that the optimal treatment may be different for each group, there may be different causes, and, for future clinical trials, it may be helpful to study specific groups separately,” Bredesen said in a statement.

The next step for the researchers is to figure out whether the subtypes have different underlying causes, and if they respond differently to potential treatments.

The finding could help in the development of more targeted research and treatments for the neurocognitive disorder.

Alzheimer's disease, long thought to be a single disease, really consists of three distinct subtypes, according to a UCLA study.

The finding could lead to more highly targeted research and, eventually, new treatments for the debilitating neurological disorder, which robs people of their memories.

The study further found that one of the three variations, the cortical subtype, appears to be fundamentally a different condition than the other two, said Dr. Dale Bredesen, the study's author, a UCLA professor of neurology and member of the Easton Laboratory for Neurodegenerative Disease Research.